Ambient References:Object Designation in Mobile Ad Hoc Networks
Tom Van Cutsem
Programming Technology LabVrije Universiteit Brussel
Brussels, Belgium
Private PhD Defense, April 30th 2008, Brussels
Promotors:Prof. Dr. Wolfgang De MeuterProf. Dr. Theo D’Hondt
Roadmap2
Roadmap2
Motivation
Mobile ad hoc networks
Roadmap2
Motivation
Mobile ad hoc networks
Characteristics
Roadmap2
Motivation
Mobile ad hoc networks
Characteristics
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Characteristics
Criteria
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Characteristics
Criteria
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Issues
Characteristics
Criteria
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Contribution
Issues
Characteristics
Criteria
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Contribution
Issues
Characteristics
Criteria
Ambient References
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Contribution Validation
Evaluation
Issues
Characteristics
Criteria
Language
LanguageFeature
Ambient References
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Contribution Validation
Evaluation
Issues
Characteristics
Criteria
Language
LanguageFeature
Ambient References
Coordination
?
Roadmap2
Motivation
Mobile ad hoc networks
Object-event impedance mismatch
Contribution
Implementation
Validation
Evaluation
Issues
Characteristics
Criteria
Language
LanguageFeature
Ambient References
Coordination
?
Roadmap3
Motivation
Mobile ad hoc networks
Contribution Validation
Object-event impedance mismatch
Implementation
Evaluation
Ambient References
Coordination
Roadmap3
Motivation
Mobile ad hoc networks
Contribution Validation
Object-event impedance mismatch
Implementation
Evaluation
Ambient References
Coordination
Context & Problem Statement
Mobile Ad Hoc Networks
Networks composed of mobile devices which communicate wirelessly
4
Ubiquitous Computing
Mobile Ad Hoc Networks
Networks composed of mobile devices which communicate wirelessly
4
Mobile Ad Hoc Networks
Networks composed of mobile devices which communicate wirelessly
4
Zero Infrastructure
Mobile Ad Hoc Networks
Networks composed of mobile devices which communicate wirelessly
4
Volatile Connections
Zero Infrastructure
Problem Statement
• Ambient-oriented Programming [Dedecker06]: traditional OOP does not scale in MANETs. How can we:
• designate objects, with zero infrastructure?
• communicate with objects, across volatile connections?
• Answer: event-based communication
• But: such communication is fundamentally not object-oriented
5
Problem Statement
• Ambient-oriented Programming [Dedecker06]: traditional OOP does not scale in MANETs. How can we:
• designate objects, with zero infrastructure?
• communicate with objects, across volatile connections?
• Answer: event-based communication
• But: such communication is fundamentally not object-oriented
5
object-event impedance mismatch
Roadmap6
Motivation Contribution Validation
Object-event impedance mismatch
Mobile ad hoc networksImplementation
Evaluation
Ambient References
Coordination
Roadmap6
Motivation Contribution Validation
Object-event impedance mismatch
Mobile ad hoc networksImplementation
Evaluation
Ambient References
Coordination
Coordination in Mobile ad hoc Networks
Characteristics
Criteria
Issues
Coordination in Mobile Ad Hoc Networks7
uMaMa
Coordination in Mobile Ad Hoc Networks7
uMaMa
Discovery
Coordination in Mobile Ad Hoc Networks7
uMaMa
Discovery Communication
Coordination in Mobile Ad Hoc Networks7
uMaMa
Discovery Communication Synchronisation
21%
32%
Coordination in Mobile Ad Hoc Networks8
uMaMa
Discovery Communication Synchronisation
Coordination in Mobile Ad Hoc Networks8
uMaMa
Failure handlingDiscovery Communication Synchronisation
Criteria for Coordination in MANETs9
Volatile Connections
Zero Infrastructure
Criteria for Coordination in MANETs9
Decentralised Discovery
Volatile Connections
Zero Infrastructure
Criteria for Coordination in MANETs9
Decentralised Discovery
Space & arity decoupled communication
Volatile Connections
Zero Infrastructure
Criteria for Coordination in MANETs9
Decentralised DiscoveryTime & synchronisation
decoupled communication
Space & arity decoupled communication
Volatile Connections
Zero Infrastructure
Criteria for Coordination in MANETs9
Connection-independent Failure handling
Decentralised DiscoveryTime & synchronisation
decoupled communication
Space & arity decoupled communication
Volatile Connections
Zero Infrastructure
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
OO Message Passing metaphor => bad decoupling
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
OO Message Passing metaphor => bad decoupling
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
OO Message Passing metaphor => bad decoupling
Survey of Related Work10
CH
APTER
3.C
OO
RD
INATIO
NIN
MO
BILE
AD
HO
CN
ETWO
RK
S45
Decoupling in Failure Decentr. MessageTime Space Synchronisation Arity Handling Discovery Passing
Languages for Local Area NetworksEmerald N (Error) N (Address) N (RPC) N Exc. N YObliq N (Error) N (Address) N (RPC) N Exc. N YABCL Y (Buffer) N (Address) Sender only N N N YLanguages for Wide Area NetworksErlang Y (Buffer) N (Address) Sender only N React N YArgus N (Error) N (Address) N(RPC) N Exc. N YJanus Y (Blocks) N (Address) N (Logic Var) N N N NSalsa Y (Buffer) N (Address) Y (Async Msg) N N N YE N (Error) N (Address) Y (Async Msg) N React N YDistributed Oz Y (Blocks) N (Address) N (Logic Var) N React N YLanguages for Wireless Sensor NetworksActorNet Y (Buffer) N (Address) Y (Async Msg) Y N N YSpatialViews Y (Mediator) Y (Discovery) Y (Mediator) Y N N NModels and Calculi for Wide Area NetworksActors Y (Buffer) N (URI) Y (Async Msg) N N N YActorSpace Y (Buffer) Y (Mediator) Y (Async Msg) Y N N YMobile Ambients Y (Mediator) Y (Mediator) Sender only N N N NTuple Space Middleware for Ad Hoc NetworksLIME Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NTOTA Y (Mediator) Y (Mediator) Y (Mediator) Y React Y NMARS Y (Mediator) Y (Mediator) Y (Mediator) Y Lease N NMiddleware for Nomadic NetworksRover Y (Buffer) N (Address) Y (Async Msg) N React N YJINI N (Error) Y (Discovery) N (RPC) N Lease Y YPublish-Subscribe Middleware for Ad Hoc NetworksEMMA N (Lost) Y (Mediator) Y (Mediator) Y Lease Y NLPS Y (Mediator) Y (Mediator) Y (Mediator) Y N N NSTEAM N (Lost) Y (Mediator) Y (Mediator) Y N N NM2MI N (Lost) Y (Broadcast) Y (Async Msg) Y N N Yone.world N (Lost) Y (Discovery) Y (Mediator) Y Lease Y N
Table 3.2: Survey of Related Work.
OO Message Passing metaphor => bad decoupling
Pub/sub & Tuple spaces => better decoupling
Object-event Impedance Mismatch11
Event broker
receiver
subscribers
me
sender
e
e
epublisher
Object-event Impedance Mismatch11
Event broker
receiver
subscribers
me
sender
e
e
e
receiver.m()publish(e)
specific interface
def m() { ...}
subscribe(e, callback)generic interface
publisher
Object-event Impedance Mismatch11
Event broker
receiver
subscribers
me
sender
e
e
eprivate designationglobal
designation
publisher
Object-event Impedance Mismatch11
Event broker
receiver
subscribers
me
sender
e
e
e
bidirectional
unidirectional
publisher
Object-event Impedance Mismatch11
Event broker
receiver
subscribers
me
sender
e
e
epublisher
threads
event loops
Roadmap12
Motivation Contribution Validation
Mobile ad hoc networks
Object-event impedance mismatch
Implementation
Evaluation
Ambient References
Coordination
Roadmap12
Motivation Contribution Validation
Mobile ad hoc networks
Object-event impedance mismatch
Implementation
Evaluation
Ambient References
Coordination
Coordination in Mobile ad hoc Networks
Language Features13
AmbientTalk
E
event loop concurrency
Smalltalk
block closures
keyworded messagestraits Self
prototypes
delegationmirrors
[Miller et al. 97]
[Ungar&Smith 87][Goldberg&Robson 83]
Scheme Agora
Pico CLOS
Event Loop Concurrency in AmbientTalk14
Actor
Message queue Event loop
Event Loop Concurrency in AmbientTalk14
‘local’ object
Event Loop Concurrency in AmbientTalk14
‘local’ object
obj
obj.m()
Event Loop Concurrency in AmbientTalk14
‘remote’ object
Event Loop Concurrency in AmbientTalk14
‘remote’ object
obj<-m()
Event Loop Concurrency in AmbientTalk14
‘remote’ object
?
future
Event Loop Concurrency in AmbientTalk14
?
future
when: future becomes: { |value| // process reply}
Event Loop Concurrency in AmbientTalk14
?
future
value
when: future becomes: { |value| // process reply}
Event Loop Concurrency in AmbientTalk14
Actors cannot deadlock
No race conditions on objects
?
future
value
when: future becomes: { |value| // process reply}
Exporting & discovering objects15
mplayer
Exporting & discovering objects15
mplayer
deftype MusicPlayer deftype MusicPlayer
Exporting & discovering objects15
mplayer
export: mplayer as: MusicPlayer
deftype MusicPlayer deftype MusicPlayer
Exporting & discovering objects15
mplayer
export: mplayer as: MusicPlayer
whenever: MusicPlayer discovered: { |mplayer| // open a session}
deftype MusicPlayer deftype MusicPlayer
Exporting & discovering objects15
mplayer
export: mplayer as: MusicPlayer
whenever: MusicPlayer discovered: { |mplayer| // open a session}
deftype MusicPlayer deftype MusicPlayer
Far References16
session
downloadSong
Far References16
session
downloadSong
Far References16
session
downloadSong
Far References16
session
Far References16
session
Far References16
session
Far References16
session
when: session<-downloadSong(s)@Due(timeout) becomes: { |ack| // continue exchange} catch: TimeoutException using: { |e| // stop exchange}
Roadmap17
Motivation Contribution Validation
Ambient ReferencesMobile ad hoc networks
Object-event impedance mismatch
Implementation
Evaluation
Coordination
Roadmap17
Motivation Contribution Validation
Ambient ReferencesMobile ad hoc networks
Object-event impedance mismatch
Implementation
Evaluation
Coordination
Ambient References
Motivation18
Second-class communication patterns
Roaming
Provisional Services
Motivation18
Second-class communication patterns
Roaming
Provisional Services
Motivation18
Second-class communication patterns
Roaming
Provisional Services
Motivation18
Second-class communication patterns
Roaming One-to-many communication
Provisional Services
Motivation18
Second-class communication patterns
Roaming One-to-many communication
Provisional Services
Motivation18
Second-class communication patterns
Roaming One-to-many communication
Provisional Services
Motivation18
Second-class communication patterns
Roaming One-to-many communication
Provisional Services
Fundamental problem: far references feature neither space nor arity decoupling
Abstractly spoken19
a
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
O
Universe O
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
s4
s1
s2
s6
s5
s3
O
Universe O
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
fa(s) = s ≡
s4
s1
s2
s6
s5
s3
O
Universe O
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
fa(s) = s ≡
s4
s1
s2
s6
s5
s3
Scope Sa = { s ∈ O | fa(s) }
Sa
O
Universe O
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
fa(s) = s ≡
s4
s1
s2
s6
s5
s3
Scope Sa = { s ∈ O | fa(s) }
Sa
Range Aa(t) = all objects in communication range at time t
Aa(t)
O
Universe O
Ambient reference a =〈 f, M 〉
Abstractly spoken19
a
fa(s) = s ≡
s4
s1
s2
s6
s5
s3
Reach Ra(t) = Sa ∩ Aa(t)
Ra(t)
Scope Sa = { s ∈ O | fa(s) }
Sa
Range Aa(t) = all objects in communication range at time t
Aa(t)
O
Universe O
Ambient reference a =〈 f, M 〉
Concretely spoken20
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
Concretely spoken20
Scope
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
Concretely spoken20
Scope
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
deftype Player;
Type tags
Concretely spoken20
Scope
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
def Player := protocol: { def askToVote(question); ...}
Protocols
deftype Player;
Type tags
Concretely spoken20
Eventual reference
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
Concretely spoken20
Delivery policies
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];
Example: Location Tracker21
def ap := ambient: LocationService;def updateLocation(newLoc) {
}
a
s1
ap<-submitLocation(id,newLoc)@[One,Instant,Oneway];
Example: Location Tracker21
def ap := ambient: LocationService;def updateLocation(newLoc) {
}
a
s1
ap<-submitLocation(id,newLoc)@[One,Instant,Oneway];
Example: Location Tracker21
def ap := ambient: LocationService;def updateLocation(newLoc) {
}
a
s1
submitLocation
ap<-submitLocation(id,newLoc)@[One,Sustain,Oneway];
Example: Location Tracker21
def ap := ambient: LocationService;def updateLocation(newLoc) {
}
a
s1
submitLocation
ap<-submitLocation(id,newLoc)@[One,Sustain,Oneway];
Example: Location Tracker21
def ap := ambient: LocationService;def updateLocation(newLoc) {
}
a
s1
ap<-submitLocation(id,newLoc)@[One,Sustain,Oneway];
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
askToVote
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
askToVote
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
askToVote
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
askToVote?
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
def players := ambient: Player where: { |p| p.team == “blue” }def handle := players<-askToVote(q)@[All,Expires(minutes(1))];whenAll: handle.future resolved: { |votes| // process the votes} ruined: { |exceptions| // ignore faulty players}
Example: Voting22
a
p2
p3
p1
Delivery Policies23
Discovery Lifetime
CommunicationLifetime
AritySustainableInstant Transient
One-way
Unbounded Bounded Expirable
@Due(t) @Expires(t)
@Sustain@Instant @Transient(t)
@Reply
@Oneway
Point-to-point@One
One-to-many
@AllTwo-way
Roadmap24
Motivation Contribution Validation
Evaluation
Ambient References
Object-event impedance mismatch
Mobile ad hoc networksImplementation
Coordination
Roadmap24
Motivation Contribution Validation
Evaluation
Ambient References
Object-event impedance mismatch
Mobile ad hoc networksImplementation
Coordination
Evaluation
Language
Criteria
Issues
LanguageFeature
Criteria Revisited25
AmbientTalk Ambient References
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Time-decoupled communication
far references + futures
@Transient, @Sustain
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Time-decoupled communication
far references + futures
@Transient, @Sustain
Synchronisation-decoupled communication
<-when:becomes:
<-whenAll:resolved:
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Time-decoupled communication
far references + futures
@Transient, @Sustain
Synchronisation-decoupled communication
<-when:becomes:
<-whenAll:resolved:
Space-decoupled communication
ambient: description
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Time-decoupled communication
far references + futures
@Transient, @Sustain
Synchronisation-decoupled communication
<-when:becomes:
<-whenAll:resolved:
Space-decoupled communication
ambient: description
@AllArity-decoupled communication
Criteria Revisited25
AmbientTalk Ambient References
Decentralised Discovery whenever:discovered: Can encode discovery
Time-decoupled communication
far references + futures
@Transient, @Sustain
Synchronisation-decoupled communication
<-when:becomes:
<-whenAll:resolved:
Space-decoupled communication
ambient: description
@AllArity-decoupled communication
Connection-independent Failure handling
@Due, Leasing @Expires
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
m
m
m
Ambientreference
receivers
sender
m
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
m
m
m
Ambientreference
receivers
sender
m
receivers<-m()specific interface
def m() { ...}
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
m
m
m
Ambientreference
receivers
sender
m
global designation
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
m
m
m
Ambientreference
receivers
sender
m
bidirectional
handle
O/E Impedance Mismatch Revisited26
Event broker
receiver
subscribers
m e
sender
e
epublisher
m
m
m
Ambientreference
receivers
sender
m
event loops
Roadmap27
Motivation Contribution Validation
ImplementationAmbient ReferencesMobile ad hoc networks
Object-event impedance mismatch
Evaluation
Coordination
Roadmap27
Motivation Contribution Validation
ImplementationAmbient ReferencesMobile ad hoc networks
Object-event impedance mismatch
Evaluation
Coordination
Implementation & Validation
Implementation28
sender ambient reference
reach
Implementation28
sender ambient referenceDiscovery
Lifetime
CommunicationLifetime
AritySustainableInstant Transient
One-way
Unbounded Bounded Expirable
@Due(t) @Expires(t)
@Sustain@Instant @Transient(t)
@Reply
@Oneway
Point-to-point@One
One-to-many
@AllTwo-way
@Annotations
message handler
!tc
n
!td
Modular implementation via traits
reach
Implementation28
sender ambient reference
message handler
!tc
n
!td
Modular implementation via traits
reach
mirror
intercept
Implementation28
sender ambient reference
dispatch
message handler
!tc
n
!td
reach
mirror
Implementation28
sender ambient reference
dispatch
message handler
!tc
n
!td
reach
mirror
Implementation28
sender ambient reference
dispatch
message handler
!tc
n
!td
reach
mirror
Implementation28
sender ambient reference
dispatch
message handler
!tc
n
!td
reachExtensional reach: collection of far references
mirror
Implementation28
sender ambient reference
dispatch
message handler
!tc
n
!td
reach
mirror
Intensional reach: M2MI omnihandles
Linguistic Symbiosis
JVMAmbientTalk
Interpreter
M2MI
Validation29
M2MI [Kaminsky & Bischof 02]Ambient References
Validation29
M2MI [Kaminsky & Bischof 02]Ambient References
Collaborative Chat
Collaborative Slideshow
Validation29
M2MI [Kaminsky & Bischof 02]Ambient References
Collaborative Chat
Collaborative Slideshow
Location Tracker
Voting
- Thread Synchronisation- Explicit callbacks- Explicit scheduling code- No dynamic attributes
Validation29
M2MI [Kaminsky & Bischof 02]Ambient References
Collaborative Chat
Collaborative Slideshow
Location Tracker
Voting
Concluding Remarks
30
Future Work31
Security: controlling visibility of exported objects & ambient references
Service Discovery: ontologies, describing services, ...
More efficient implementation strategies
Conclusion
• Ambient-oriented Programming = “OOP in MANETs”
• Object communication: decoupled in time & synchronisation [Dedecker 06]
• Object designation: decoupled in space & arity
• Ambient references: intensional remote object references
• Unification of OO and event-based publish/subscribe interaction
32
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